Unfortunately building and fixing things (or just keeping things working, negotiating compromises, and so on) takes a lot of time and effort, and doesn't make for great pithy slogans or rile people up.
Biden in fact was the worse Democratic President for not stepping aside early enough and letting the DNC have a real primary. It was sheer selfishness and ego.
Results count - not excuses.
They were lying through their teeth. Biden had already fixed the crisis. Trump's undone that work, and is now going around claiming to have fixed stuff.
One example is how Trump is going to get a bunch of people to build factories in the US:
https://fred.stlouisfed.org/series/C307RC1Q027SBEA
Biden also got the inflation caused by Trump's ZIRP + deficit spending under control, despite digging us out of COVID. (The inflation surge during Biden's term had already been predicted by most economists by the middle of Trump's first term. NPR even ran a series about "printing unlimited money bad" in 2018 or 2019.)
Also, Trump inherited the lowest crime rates in living memory, and then declared a national emergency about surging crime.